Categories

Meta

math

Mae govannen, Mellon! Tolo ned; dortho. What’s that? You don’t speak Elvish? I said, “Well met, Friend! Come in; stay.” Don’t worry about which words mean what – just trust me; that’s the phrase. All you have to do is remember it, and you will speak Elvish too!

Okay, you’ll probably need a little more to get by, so if you run into trouble you should also remember Noro lim! (It means, “Run fast!”) Got it memorized? You may also want to practice saying them out loud so you can pedo (speak) well. If I’m throwing too much at you too fast, just ask me to daro (stop) – but I bet if you drill with some flashcards you’ll be able to absorb it soon enough.

Welcome to the Elvish-speaking world!

What, you don’t quite feel fluent? Of course you don’t; this is a completely ridiculous way to teach someone a language. Maybe you could hold down a job as a greeter at a Grey Havens jogging track (“Come in! Run fast!”). At best you could train an Elvish dog. But you certainly won’t be chatting with Elrond about the merits of mithril anytime soon.

If you have ever learned a language – and if you are reading this, I know you have – you know that an alphabet and some common phrases are not enough for conversation. We need vocabulary, and syntax. We need an understanding of the rules. In short, we need grammar.

And yet, for generations we’ve been teaching the language of math just like I taught you Elvish.

Learn those letters (digits 0 through 9); sing the alphabet so you can remember their order (counting); memorize these combinations and what they mean (drill those times tables); and BOOM. Good luck communicating!

The human brain is an amazing thing that can commit an impressive amount of information to memory – especially if it is useless – but after a certain point it just can’t memorize any more. Without some grammatical rules to govern things, the wheels rapidly fly off the Math Mobile. (At around fifth grade, for most people.)

Fortunately, education specialists know that learning logic is just as important for math “numeracy” as grammar is for literacy. Which is exactly what the Common Core sets as the new goal* of early math education.

[*I say “goal” because the Common Core is a collection of skill goals for each age and subject around which teachers and schools design specific curricula. It is not a set (or dictated) curriculum itself.]

Yeah, math homework looks really weird now, but that’s because – in addition to the old carry-the-one remainders method of doing math on paper – kids are first learning to think of numbers as collections and combinations of other numbers. They are learning the logic of math instead of just the labels. Like how a language speaker can look at a word she has never seen before and use prefixes, suffixes, and roots to figure out the definition anyway.

When a person who is “good at math” does subtraction or division in her head, she doesn’t line things up on top of or next to each other and fiddle around with carried numbers. No, she looks at your weird Facebook post celebrating your child’s 31st week of life and thinks that 31 is almost 32, which is itself made up of eight fours, and since there are four weeks in a month calculates that your child is just under eight months old because that’s the way normal people mark time, Thank You Very Much.

If that isn’t how you do math in your head, I am betting you probably don’t consider yourself “good at math.” Our kids, on the other hand, will be, and that will benefit everyone.

Is it annoying that future generations are going to know how to do stuff better than we can? Absolutely. Kids already think they know everything and this is only going to make them more obnoxious. But fighting against numeracy (or the Common Core in general) because “that’s not the way we learned it” makes about as much sense as going back to treating acne with urine. (Yeah, we used to do that apparently. Ew.)

Now, if you want to fight all the standardized testing, that’s a completely different issue. I will be right there burning the No. 2 pencils and bubble grids beside you. Tol acharn! (Vengeance comes!)

There need to be more math-inspired food holidays, and together you and I can make that happen.

Wasn’t Pi Day fun? Even though this year (3/14/15 at 9:26:53) was the Pi Day of the Century, March 14th is a great excuse to eat pie in any year. But, just as they say that there are 10 types of people in this world: those who understand binary and those who don’t, the world is also divided into those on team pie and team cake.

As much as I love the number pi, I am decidedly a cake girl. It was the source of great friction in a relationship once, even after I baked a Cherpumple to bridge the gap with my pie guy. (A Cherpumple is a cherry pie baked inside a chocolate cake on top of a pumpkin pie baked inside a spice cake on top of an apple pie baked inside a vanilla cake. It is a foot tall, weighs 18lbs and feeds about forty. Epic.)

So what other math-food holidays can we celebrate, preferably without sparking dessert wars?

We can stick to the irrational number world and celebrate “e Day”. Since e is the natural log, we could eat ants on a log, cheese logs, yule logs (the cake kind) and basically any other roulade. But e is approximated as 2.7, and February 7th has come and gone.

Famous ratios might be the answer, like the Pythagorean Theorem’s “a squared plus b squared equals c squared” relationship between the sides of a right triangle. This gives us the classic 3:4:5 triangle ratio, so we could have eaten triangular foods (pizza, baklava, candy corn) on March 4, 2005 (3/4/5) or June 8th, 2010 (6/8/10). Unfortunately, Pythagorean Theorem days require all three numbers, and even though the next one is September 12th, 2015 (9/12/15), I’M HUNGRY NOW.

Square root dates have the same need for three numbers that makes them rare – such as 2/2/4, 3/3/9, and next 4/4/16 – and besides, do we want an entire meal made up of root vegetables?

There is always the Fibonacci Sequence (my personal favorite), which runs 1,1,2,3,5,8,13… etc., adding the preceding two numbers into infinity. This number is traditionally celebrated on November 23rd (11/23), but could also be feted on 1/1/23 when it comes. Since Fibonacci formulated the sequence after a thought experiment about mating bunnies, we should all make like Elmer Fudd and hunt some wabbit.

Or, since the Fibonacci Sequence also defines the Golden Ratio – another irrational number, roughly 1.618 – we can celebrate the hell out of it on January 6, 2018. The rich can eat foods dusted in gold flakes and gold powder; the rest of us can meet up at McDonald’s.

Still, these dates are years away. I want math-inspired food NOW!

Our answer is the humble mole. Not the blind, hole-digging insectivore, nor the irritating, cancer-threatening skin growth; I mean the massive constant defined by the number of molecules in 12 grams of Carbon-12 – specifically 6.022 times 10 to the 23rd power.

Think about it: a mole is a unit of measurement in chemistry, and mole (“mo-lay”) is a delicious Mexican sauce made with chocolate and spices, so the food tie-in is natural and fantastic. Plus, the number of things in one mole of anything (6.022 x 10^23) is also known as Avogadro’s Constant; ‘Avogadro’ is so close to ‘avocado’ it’s like the food gods are daring us NOT to do this. A mole dish with avocado? Yes, please!

Finally, Amedeo Avogadro (for whom the number is named) was an Italian Count born in 1776 (freedom!) who studied and practiced law (litigiousness!) before inheriting his father’s title and enough money to retire and dick around with science (financial privilege!). What’s more American than that? This should absolutely be a national holiday.

Oh, sure, I know people already celebrate Mole Day on October 23rd at 6:02, but just as some people celebrate Pi Day on July 22nd (because it can also be approximated as 22/7 and Europeans write their dates day/month), we can certainly have two Mole Days. And, yes, it would make more sense to do it on June 2nd instead of June 22nd, but I missed that day, so screw it.

JOIN ME on June 22nd at 10:23 (am or pm is your choice) in eating a delicious Mexican dish of any type so long as it is slathered in mole sauce and accented with avocado.

Once upon a short time ago, I spent over twenty minutes arguing with a Time Warner Cable representative about how math works.

My monthly cable bill had suddenly increased by $7 (increased again, I should say, because this was not the first time), so I had looked and found a new $7 charge listed for the modem. (The modem I had been using for no charge since…always.)

The TWC representative tried repeatedly to convince me that they had always been charging me $7 for the modem, it’s just that now they were listing the fee as its own line item on the bill. I replied that if that were true my bill total would not have increased (because, math), but it had increased, so there was clearly a new charge for something, and would she please just fess up to it already.

After twenty minutes of our own little version of Waiting for Godot (“I recognize that tree!”) she finally succumbed to the power of how numbers work and agreed there was a new fee. I agreed to no longer be a Time Warner Cable customer.

While I appreciate that this woman provided the kick I needed to finally bail on cable, our conversation makes me want to bang my head against a wall. For six years, I have spent much of my time helping adults prepare themselves for the rigors of law school, and in that time I have been repeatedly surprised and disheartened – as I was on that phone call – with the general lack of logical reasoning employed by humanity.

Logic is important, even if only to save us from Kafkaesque conversations and murderous thoughts. If we used it more, our civilization would be in a much better place.

For one thing, logic allows us to recognize when people (and cable companies) are lying. It demands reasons and facts be given to support arguments – including our own. With logic, we also recognize when a statement is technically true (“That Awkward Moment is the #1 comedy of the year!”) but essentially meaningless (“Dude, it’s still January”).

Even more relevant to our current state of debate, logic helps us stay focused on the actual point, instead of getting distracted by more convenient statements that are off topic. Sure, mental health and how we treat it is a major problem in the world, but it isn’t a relevant rebuttal to “I think there should be more gun regulation,” any more than “vegans are annoying” addresses whether we should let the pregnant pigs move around, or “I hate science” is an argument against global warming.

Most importantly, though, logic is vital because it exercises a skill that is crucial to human success: creative thinking.

It is no coincidence that Einstein was a skilled violinist while Hitler was a bad painter; creativity and reason go hand in hand. To be logical is to be able to mentally entertain as many possibilities as can be imagined and then evaluate them against whatever facts are known. It is to know that there was a mass extinction of dinosaurs, imagine the infinite reasons it could have happened, and use the evidence of meteor strikes, lack of evidence of spontaneous combustion, and miniscule likelihood of alien invasion to conclude that most likely the meteors were the culprit.

(It is also to know that the limited facts demand language like “most likely” instead of “of course it happened that way, how dare you question me?!” or “I don’t believe you so no it didn’t!”)

Logical thinking trains us to have flexible minds, which is the ultimate reason it needs to be more prevalent in our world today: because mental flexibility is the key to empathy. Yes, it also helps if we have and understand emotions, but empathy by definition requires the ability to think beyond our own personal situation.

In college, I was once asked by a boy (he was a boy in every sense) why I was pro-choice; to answer him, I started by saying, “given my own health issues, I can certainly imagine why someone might need-“ and he cut me off by rebutting, “It’s not about YOU. You’re so selfish.”

His statement was technically true – it wasn’t about me – but meaningless, because it WAS about my ability to put myself in another person’s shoes; to imagine circumstances that, while not true for me, may be true for someone in a different place or time or dimension.

A rigid “I would never” is not enough to close the book on any subject. That’s great that we would never; it is completely our right to choose to “never” – but somebody would, and shouldn’t we at least take the time to explore and understand their reasons before we judge?

Without empathy, progress can only happen once everyone personally knows a victim of sexual assault, a minority being denied rights, a dark-skinned person who has suffered harassment by those in authority, or someone forced to make a bad choice in a bad situation. Of course, the sad fact is, everyone already does.

Confession time: I write romantic comedies for a living, and I do not believe in The One.

Before anyone takes away my pen and paper, let me clarify – this is not a Nicholas Sparks situation where my cynical outlook toward humanity and borderline-misogynist opinion of women drives me to churn out one crassly formulaic story after another. I absolutely believe in love, soul mates, true partners, and all that crap; I just don’t believe each of us has only One.

Both my head and my heart reject the idea. Already, in my short time experimenting with love, I have met at least two men with whom I am sure I could have enjoyed spending the rest of my life. The fact that things didn’t work out doesn’t make them – or our relationships – any less wonderful.

As for my brain, the idea of The One is straight-up depressing on a practical level. There are 7.2 billion people on the planet, most of whom – even with the internet – we will never meet. What if someone’s One lives in North Korea? Tough?

But I like proof when possible, and astrophysics can provide: The Drake Equation is a formula developed in 1961 by astronomer Frank Drake to calculate the probability we will ever detect intelligent alien life in the universe. Since men are from Mars and women Venetian, I figure it applies.

While the actual Drake Equation is impossible to calculate (so far) because most of its variables are unknown (for now), it is pretty simple in essence. Just a straight multiplication of the probabilities of various factors necessary for finding E.T. – like that aliens exist in the first place, or have detectable technology.

Specifically (hang in there) it looks like this: N = R*Fp*Ne*Fl*Fi*Fc*L, which looks completely like gibberish until you know what all the shorthand stands for. Let’s do it!

N stands for the number of alien civilizations we can detect. In other words, it is the answer we are looking for – it is the number of The Ones.

R is the rate at which stars form in the universe, so for mate searching it is the rate at which humans form. According to P.T. Barnum, there is one born every minute, so let’s say R = 1.

Fp is the fraction of stars in the universe hosting planets. Equivalently, let’s call it the fraction of persons with the proper parts for one’s sexual orientation. Whatever your preference, that should be ½, but I (a heterosexual) will remove another ten percent because supposedly that’s how much of the population is gay. Fp = 2/5 (aka 40%).

Ne is the fraction of planets that pass the “Goldilocks” test, or in other words are suitable to sustain life. For sustaining a relationship, this would be the fraction of the population between, say, 25 and 55, which is 1/6 of humanity.

Fl is the fraction of Goldilocks planets with actual life, which I will translate as the fraction who possess the first piece of the relationship P.I.E. – Physical attraction. This is where things get harder to calculate, but I’ll base it off my own experience. Let’s say I’ve met about 10,000 people in my lifetime. (I have lived in three major cities, traveled a lot, and been a performer all my life, so this is fair.) There have probably been about 200 to whom I have been attracted enough to want to sleep with them (don’t worry, Dad, I didn’t). So that makes Fl = 1/50.

Fi is the fraction of life-bearing planets with intelligent life, and that perfectly corresponds to the second piece of the relationship P.I.E. – Intellectual stimulation. I’d say I’ve met about 25 men I felt I could keep talking to forever, and 25 out of 200 is 1/8.

Fc is the fraction of intelligent life that possesses the technology to make themselves detectable. For a life partner, that means having the last piece of P.I.E. – the Emotional support to sustain a relationship. There have really only been two men in my experience with all three pieces, so this last fraction is 2/25.

Lastly comes L, which in the Drake Equation represents the length of time any technologically advanced alien race will remain actually detectable. (For our civilization it has only been about 100 years so far.) In terms of humans, this is the serious dating window. Let’s go with 20 years, which at 365.25 days per year, 24 hours per day, and 60 minutes per hour comes to 10,519,200 minutes. If you want to check my math, ask someone from the cast of Rent.

Putting it all together, we can see that my N (number of ‘Ones’) equals: 1 sucker per minute, times 2/5 who are heterosexual men, times 1/6 at a datable age, times 1/50 who are physically appealing, times 1/8 also intellectually stimulating, times 2/25 with the trifecta of emotional support, all multiplied by 10,519,200 minutes of partner seeking.

The result: 140. There are 140 The Ones for me on Earth.

Of course, my numbers are largely anecdotal and would never pass the scrutiny of peer review, but the point remains – no way is there only One perfect partner. In fact, if we use the actual rate of human birth – 267 per minute – the number comes out to be 37,380 The Ones. Which is almost exactly the population of Bozeman, Montana. (For real; it’s off by about 100.)

37,000 ideal potential mates seems like a lot, but that’s on the whole planet. Add in that we also have to meet them, and (preferably) speak the same language, and both be available at the same time… the number whittles down quickly. If we’re lucky, we experience maybe a handful in our lifetime. And then they have to want the relationship too.

When you consider that a “forever” relationship requires three major things to happen in unison – first, we have to be ready for the responsibility ourselves; second, we have to meet one of the 37,380 potential partners; and third, that person has to also have decided they are ready for a grown-up relationship – it is no wonder it feels like there is only One magical person out there.

Patience is definitely called for. Or, perhaps, a move to Bozeman, Montana.

In 1960, Smokey Robinson’s mama dropped some serious truth when she insisted he better Shop Around. Given the decade, Smokey probably assumed her wisdom came from a woman’s deep understanding of bargain shopping, but I prefer to think she was simply keeping up with modern trends in mathematics.

Around that same time, numbers guys around the world were turning their attention to a decision-making dilemma they dubbed The Secretary Problem (also The Marriage Problem). Since the parameters of the problem are applicable to many real world situations, and since I choose not to indulge the sexist world of the Mad Men era, I call it the Ice Cream Headache.

Imagine yourself in an ice cream shop facing dozens of flavor options. You have to decide on just one, and ideally you want to choose the very best of all. The rules are simple: first, your choices are finite. (Even though Baskin Robbins lies and offers more than 31 flavors, they still don’t offer “infinity” flavors.) Second, you can sample flavors, but only one at a time, only once each, and you must make a decision immediately upon tasting – choose it, or pass. Finally, there are no ties. One is decidedly the best (for you).

To maximize your chances of walking away with The One, it turns out “shop around” really IS the best strategy – to a point. Mathematicians came to find that the optimal approach is to always reject the first 36.7% of flavors you try (that happens to be 1/e for all you natural logarithm fans out there), then choose the next flavor that tastes better than anything that has come before.

Say there are nine flavors total. This optimal method means we will taste the first randomly selected three and not choose them, no matter what. The odds of The One being in those first three (which means we will definitely NOT win the game) is 33%. The other 67% percent of the time, we still have a chance.

After rejecting the first three, we will choose the very first flavor that tastes better. If we happened to taste the second best flavor in the first three but not The One – the odds of which is 25% – we are guaranteed a win. Only The One will taste better, so only The One will be chosen, no matter how long it takes us to get to it. The remaining 42% of the time, victory depends on when in the subsequent tastings The One appears.

When the math is said and done, probability shows that employing this strategy to the Ice Cream Headache results in victory – choosing The One – at minimum 37% of the time, which is the best chance possible and far better than choosing at random.

Sure, in real life we are free to piss off the ice cream vendors as we test every single flavor over and over until we are either satisfied with our decision or just satisfied, but the parameters of the Ice Cream Headache are remarkably realistic when it comes to dating.

In love, we generally get one shot at evaluation – Burton and Taylor notwithstanding. Likewise, the choice is usually a now-or-never situation. (We may dream of “sampling” a person and then getting to try all the other people too before ultimately deciding, “You are the best,” but in reality that ends with a “Screw you, I’ve moved on” and a drink in the face.) Finally, even with today’s online resources, we still have a finite number of candidates.

Applying the lessons of the Ice Cream Headache to a partner search yields some interesting results.

For one, it helps redefine the idea of “success”. We usually view situations as win or lose, but mathematics has a third option: draw. Victory in the Ice Cream Headache is walking away with The One, but failure isn’t everything else; failure only happens if we walk away with a flavor that is NOT the best. Remember that 33% chance The One was in the automatically rejected first group? In that case, the player would never choose any flavor, because nothing would ever meet the requirement of outperforming everything prior. In life terms, the player stays single. I like the idea of a single life being a “draw” rather than a loss.

More significantly, the Ice Cream Headache validates the practice of living a little before settling down. The average life expectancy of an American woman is 82 years; 77 for American men. If we apply the “discard the first 36.7%” rule, no one should even consider choosing a life partner before age 30 or 28, respectively.

To apply the strategy more specifically to our dating years, let’s say no one dates seriously before 15, and we reserve the last 10 years for writing memoirs and bowling. That leaves 57 shopping years for women, and 52 for men. Again, if we automatically pass on the first 36.7% of candidates, that translates to 20 years of dating before possibly making a choice (19 for men). Starting at 15, that pushes the start of decision time to our mid-thirties.

Yes, this simplifies things with the premise that potential mates will appear at a steady rate across our dating years (now more likely with the internet), but the end result is still valid. Statistically, the optimal strategy over a lifetime for successfully ending up with your ideal flavor is to not get serious about choosing until sometime after 30. Mama was right: you better Shop Around.

Of course, this still doesn’t solve the problem of that awesome mocha chip gelato you finally go for deciding he doesn’t want you. But it helps.

Okay, kids, let’s get down and nerdy for a little bit. Fair warning: there will be math in today’s session. I promise to make it fun and not scary (says the former captain of her high school math team), and I assure you there will be no test after. To every student past, present, and future who ever rolled his eyes to the heavens in math class and asked, “When am I ever going to use this in real life?” I answer with the eternal wisdom of Shania Twain: “From this moment on.”

I have been reading about Bayesian reasoning lately (in Nate Silver’s awesome book about prediction – and if that surprises you at all, I invite you to glance up at the title of this blog one more time), which is a school of probabilistic thinking employed by, among others, the most successful gamblers. According to Marvin Gaye (and confirmed by anyone who has ever been willing to eat at a Taco Bell), life is a gamble, so I naturally wondered how Bayesian reasoning might apply to areas more relevant to me than sports betting. Now, I consider myself a fairly logical and scientific individual – mostly because I am ridiculously logical and scientific – but what I came to realize about my approach to other humans kind of blew my mind.

A little background: Thomas Bayes was an 18th century English minister who sought to resolve the paradox of a benevolent God and the existence of evil. See? I told you this would be fun. In very brief terms (my apologies to any theologians or philosophers our there), his answer revolved around the idea that the imperfections we see in the world are ours, not Gods, because our knowledge is never complete. In other words, if we see too much evil in the world, it doesn’t mean that there isn’t overall good, but rather that we are not seeing the whole picture. I’ll save the larger debate about good versus evil for my next Lord of the Rings party, but what matters most is that Bayes introduced the concept that humans learn about the world through approximation rather than certainty – getting closer and closer to the truth with each new piece of the puzzle, but never knowing the absolute truth.

Bayes’s chief rival in those days was David Hume, a Scottish philosopher to whom I’m going to give the benefit of the doubt and assume was drunk a lot, because he equated rational belief with certainty. Talk about depressing. Here’s a quick example to demonstrate the disparity: imagine you have moved to Los Angeles with no prior knowledge of it climate, history, or reputation, presumably because you have never seen a movie, read a book, watched TV, or met a Californian. This makes you either an alien or Amish, but I digress. Day 1: it is sunny. Aw, that’s nice. Day 2: sunny again. Cool. Perhaps this is a trend. Day 3: still more sun, and so on, and so on. The Bayesian thinker will grow more confident with each passing day that tomorrow’s weather is likely to be sunny – never fully reaching 100% certainty, mind you, but getting darn close. Even when, 300 days in, it suddenly rains (in case you haven’t heard, we’re experiencing an epic drought here in LA), the Bayesian will still be pretty sure the next day will be sunny. Those on Team Hume, on the other hand, reason that since we can’t be certain about tomorrow’s weather, it is equally rational to predict sun and rain. This sounds like a pretty high-stress way of life to me, and a recipe for an early ulcer. No wonder he drank.

Now we’re all caught up: Bayesian reasoning balances past knowledge with new information to make a probabilistic prediction about what is true, while those on Team Hume remain susceptible to the false positive – when the newest info is given disproportionate importance. I don’t know about you, but one seems like a far more productive way to interact with the world. (And if you think I mean the second way, then, well, you should run for Congress. You would do well there.) But when it comes to pursuing the opposite sex, or the same sex, or just sex in general, we tend to drop Bayes like a hot potato and make out with Hume every time.

First date went well? We’re in love! No word for the next two days? He hates me! Got asked out in a clear, direct way? Hooray, a grown up! Got cancelled on a few days later? What a flake; it’s over. In relationships, we tend to ignore the past entirely in favor of how we are feeling right now (it’s raining today and thus will never be sunny again), OR deny the probable with the excuse that we can’t know for certain (sure, he hasn’t called for three weeks, but maybe he was unexpectedly sent to space; YOU don’t know). Either way, there is going to be a lot of anxiety and crying over what is – to be all cold and scientific for a second – just one new piece of data.

To be Bayesian in life, we must consider not just the newest information, but also the weight of everything else we have learned up to this point. This is easier than it sounds, but brace yourself: here comes the math. In Bayes’s theorem, when new information comes in (an event occurs), we must consider three specific things before we can make a probabilistic guess at the truth. Let’s make our “new event” one to which we can all relate: he asked for your number (email, Twitter handle, whatever), and then didn’t call (text, write, tweet, you get the idea). According to an entire franchise, this means without question that he is just not that into you. But to really judge the truth of that, Bayes asks us to evaluate the following:

First is the probability that, if it IS true – he is NOT into you – he would ask for your number and then not call. This is variable Y. It seems weird that someone not into you would ask for your info, so our instinct might initially be to set this probability low. But then again, there is social convention to consider, as well as alcohol, the existence of sadists, and the fact that this is Los Angeles where people are always hedging their bets, plus there is the actual fact of his not calling…so let’s say there is a 75% chance of someone NOT into you still asking for your info but then not calling. Y=0.75

Next we have to consider the opposite – the probability of someone who IS into you asking for your number but then not calling. This is variable Z. As a female, I can come up with a million possible reasons for the lack of call: maybe he lost my info, or his phone, or maybe he’s scared, or hasn’t broken up with his current girlfriend yet, or maybe he works for the CIA… But I am going to let the rational part of my brain step in and acknowledge that, while possible, all together there is still at most probably a 20% chance of any of these being true. Z=0.2

Finally, and most importantly, is what Bayesians refer to as the prior – the probability before the event, before knowing anything about this particular guy or situation, that any guy you meet would NOT be into you. This is variable X. This is also where self-esteem comes to play, so let’s start with a neutral 50%. X=0.5

Once you have assigned those probabilities, the math is pretty simple. The probability of it being true that his is, in fact, NOT into you is the fraction: (XY) over [(XY) + Z(1-X)]. In plain English, it is the probability of ANY guy being not into you multiplied by the probability of a guy being not into you and not calling (XY), divided by that product (XY) plus the probability of any guy being INTO you (1-X) multiplied by the probability of him being into you and not calling (Z). With our numbers, that is: (.5)(.75) / [(.5)(.75) + (.2)(.5)], which comes out to 0.79. So, yeah, there is an almost 80% chance he isn’t into you – but a far cry from the 100% chance that it feels like in the moment.

What I love most about this, though, is how it shows with math the effect that our own personal outlook changes the way we react to things (or should react to them). A person with very high self esteem would probably have a low prior – say, a 10% chance that any random guy would NOT be into her. When X gets changed from 0.5 to 0.1, the lack of phone call results in only a 29.5% chance that he isn’t that into you. We become more willing to consider the event a false positive. But if we have a low opinion of ourselves – say, a prior of 90% (and if this is you, listen to some Katy Perry or go hug a Muppet or something, stat) – one missing phone call results in a 97% chance he isn’t into you. Devastating. So, if you find yourself reeling from every little dating hiccup, take a hard look in the mirror and re-evaluate your priors. Also, find a friend to tell you how awesome you are – and listen.

Besides protecting us from the imbalanced impact of a false positive, Bayesian reasoning also defends against being that sucker who believes Adam Sandler could actually be a secret agent, because the idea is that we re-asses our reality with each event. Instead of treating each time he doesn’t call as a new event to be reasoned and given the benefit of the doubt in isolation, we absorb them and allow them to affect our prior. One last time, let’s set our variables: we will keep Y at 75% and Z and 20%, but let’s go for a normal, healthy prior of 30% – a 30% chance any random person wouldn’t be into you. When he doesn’t call the first time, this calculates out to a 61.6% chance he isn’t into you. This becomes our new prior for this guy (rounding down to 60% for the sake of headaches). Now, when we go out and run into this guy again, and he is flirty and attentive again, and then doesn’t call or communicate again (you know who you are), we calculate the probability that he isn’t into us with an X-factor (not to be confused with an American Idol) of 60%. That results in an 85% percent likelihood of his disinterest. And if it happens a third time (again, you know who you are, and I am NOT amused), the prior is set at 85% and Bayes’s theorem calculates a 95.5% chance he is not that into you. Time to write the boy off, for sure!

Bayesian reasoning allows us to learn and grow from experience, rather than repeat the same mistakes by coming at the world from a place of willful ignorance. Every failed relationship has something to teach us about what we do or don’t want in the future, until ideally we know enough to get one right. That is exactly the idea behind Bayes’s probabilistic thinking – it is the path, through logic, to less and less wrongness. We can’t ever be 100% certain about what is in another person’s heart or mind. But if we are willing to apply a little patience and, yes, math, we can get to a level of confidence that allows us to trust the gamble and win big.